Method of making envelopes



Nov. 28, 1967 R. WINKLER ETAL 3,354,793

METHOD OF MAKING ENVELOPES Filed Aug. 5, 1965 Lf" l\ .-Q N DEW f 0u L 3K H nl 0 .ag m N Q8 En@ @a a N@ -Q u D N Ll. II t\ NN N y iQ. N M

N N 1 N Q .13 N LL United States Patent O 3,354,798 METHD F MAKINGENVELPES Richard Winkler, Enrgernieister-Wink-Strasse, Rengsdorf,

Germany, and Kurt Diinnehier, Am Birken-thang, Gladhach, Germany FiledAng. 5, i965, Ser. No. 477,558 Claims priority, application Germany,Aug. 20, 1964, W 37,416 14 Claims. (Cl. 93-63) The present inventionrelates to a method of manufacturing envelopes, especially open-endenvelopes in continuous operation, and more particularly, to a method ofmanufacturing in continuous operation envelopes from blanks whichincluding bottom, side and closure flaps consist of a single piece cutfrom a continuously fed web, such as a paper web.

There are known several methods of producing envelopes from one or alsotwo continuous webs by gluing the webs along both lengthwise sidesthereof. With these known methods, as many operational steps as possibleare carried out on the continuous web or webs before the more or lesscompleted envelopes are separated from the web.

To produce envelopes of different lengths and widths preformed sideflaps, bottom flaps and closure flaps from a continuously fed web,cutting rollers of a specific diameter must be used for the length ofthe different envelopes to be produced, since the circumference of thecutting rollers must equal the development of the blank for therespective envelope. The same is true for cutting window openings intothe continuously fed web from which the blanks for making the envelopesare cut. The inventory of cutting rollers and the cutting tools propermounted thereon which must be maintained for producing envelopes ofdifferent lengths is expensive and the time required for resetting amachine from one length of envelopes to another length is considerable.Accordingly, unless the envelope machines are used for producing a highrun of only a few dimensions of envelopes, machines of this kind are noteconomical in spite of the saving of paper and in punching or cuttingoperations when a continuous web is used as starting material.

It is -a broad object of the invention to provide a novel and improvedmethod of producing at bags or envelopes, particularly large sizedenvelopes in a more economical fashion than is possible with methods forthe purpose as heretofore known.

The aforementioned object, feature and advantage and other objects,features and advantages which will be pointed out hereinafter are-attained by feeding a web at a uniform rate of speed past a cuttingdevice which cuts the web crosswise into successive rectangular pieces.Each of these pieces constitutes a preliminary or raw blank, the widthand length of which correspond substantially to the width and lengthrespectively of the envelope to be produced. The blanks are acceleratedto a higher rate of travel, preferably to a speed such that one envelopeblank is cut per revolution of the cutting rollers. The moving blanksare subjected one by one to further cutting operations until the desiredfinal outline of the blank is obtained, that is, a blank defining therequired side aps, a bottom fiap and a closure fiap. The flaps are thenpref folded, coated with adhesive and nally folded upon one another.

It is preferable to change the direction of travel of the blanks afterthe fiaps thereof are cut so that the initial lengthwise orientation ofthe blanks remains unchanged for -a purpose which will be more fullyexplained hereinafter.

It is also an object of the invention to provide a meth- ICC od whichpermits the use of different types of adhesive and also of differentfoldings of the bottom and closure flaps.

The method of the invention will be more fully explained in connectionwith the accompanying drawing which shows diagramm-atically flow sheetsfor producing single piece envelopes.

In the drawing:

FIG. 1 is a flow sheet showing the manufacture of onepiece envelopesbeginning with the feeding of a continuous web and ending with completedand stacked envelopes;

FIG. 2 is a modification of the sequence of the steps required forgurnrning the bottom and closure flaps of the envelopes;

FIG. 3 is another modification 0f the operational steps required forgumming the bottom and closure fiaps; and

FIG. 4 is a modification of the path of travel of the blanks during theprocessing thereof.

The invention provides for applying a single gluing of the envelopesalong the mid-line thereof and it also provides for a single lateralgluing of the mid-portion of the envelopes. It further discloses threedifferent methods of gumming and of folding the bottom and closure flapsof the envelopes.

It should be understood that the tools required for cutting the blanks,applying adhesive thereto, folding the blanks and stacking the finishedenvelopes do not constitute part of the invention. All these toolsshould be visualized to be conventional and are hence not illustrated ordescribed in detail.

Referring now to FIG. 1, the flow diagram shown in this figureillustrates a continuous web 1, such as a paper web, which is suppliedfrom a supply reel (not shown) and travels along a rectilinear path inthe direction of the arrow at a predetermined uniform speed. The width Bof the web should be visualized as corresponding to the width of thefinished envelope to be produced. At a selected point of travel, crosscuts 2 are made by a suitable cutting device, such as a rotary cutter,to produce successive rectangular preliminary or raw blanks 3 with thelength L. The blanks 3 are immediately accelerated to the working speedof the envelope making machine Whereas the length L of the blankscorresponds to the lower rate of travel of web 1 per operation of thecutting tools. As la result of the yacceleration of blanks 3, lengthwisegaps D are formed between each two blanks.

Prior to the cutting of the web, for instance, in the position indicatedby xx, the web may be printed on one or both sides. Since the rate oftravel of the web is equal to the length L per operation of the cutter,the printing rollers must have a diameter correlated with the length Lunless it is desired to cover the entire surface of the web with print.However, this limitation which must be observed to obtain a Asuitablediameter of the printing roller is more than balanced by the long dryingpath which is provided for the print on the moving web.

In the station or position 5, marginal portions 8 are cut off from theblank by suitable rotary cutting tools to define a bottom flap 6 and aclosure flap 7. The blank has now its final outline.

The outline of the blank as illustrated in position 5 is designed formaking envelopes glued at the mid-line thereof. In the event envelopesglued along a side are to be produced, the blank must be cut as it isshown in the station or position 5', that is, the cut-out portions 8 areshaped to produce the bottom flap 6 and the closure fiap 7. Both shapesof the blanks may be cut with the same cutting tools.

In the station or position 9, preliminary fold lines 10 are formed bysuitable folding devices, such as a rotary f3 D straight scoring meansand an elastic counter roller. The scoring means and the roller areadjustable in reference to each other. The preliminary fold lines 1t)serve to facilitate the later final folding of the flaps.

In the station or position 11, each blank is turned Athrough an angle of90 in reference to the initial path of travel of the web. In the eventlack of space makes it difficult to provide an angular path of travel inthe enyelope making machine, the blanks themselves are turned through anangle of 90 by means of a suitable device,

such as a turn-table as it is indicated at station or position 11' inFIG. 4, but continue along the initial path of travel.

Otherwise, the processing of the web and later on of .the blanks iscarried out in the arrangement of FIG. 4

and the closure flaps thereof.

lIn the station or position 14, preliminary fold lines 1S are made todefine two side flaps 21 and 22. These fold Vlines for the side aps maybe formed in the same manner as has been described for the fold lines ofthe bottom flap and the closure flap in connection with position 9.However, vit is also possible to produce fold lines and 15 in immediatesuccession, that is, the positions 9 and 14 may be adjacent to eachother.

In lthe station or position 16, one or several windows r17 are cut intothe blank by suitable rotary cutting means.

In the station or position 18, windows 17 are covered by a suitabletransparent foil of film 19 which is glued to the `blanks in aconventional manner.

The positions 16 and 18 may be omitted if envelopes fwithout ywindowsare to be produced. In an envelope making machine for carrying out themethod of the inyention, the tools required in positions 16 and 13 arepreferably arranged as optional or detachable tools.

In the station or position 20, the bottom Vap 6 and theclosure flap 17are rst folded along the preliminary fold linesfand arethen openedagain.

yIn the station or position 23, the leading side flap 21 is folded overas shown along its fold line by a suitable folding tool.

In the station or position 25, a stripe 26 of a suitable adhesive isapplied to the trailing side flap 22.

In the station or position 27, the gummed side flap 22 4is folded backupon .the previously folded side flap 21 so that the side aps are nowadhered to each other.

After folding and gumming of the two side flaps, the rate of travel ofthe blanks is preferably reduced to about half the speedbycorrespondingly reducing the diameter of the transport rollers of themachine.

In the station or position 28, stripes 30 and 31 of the adhesive aresimultaneously applied to the bottom flap and the closure flap.

In the station or position 29, the bottom flap 6 is folded back upon thepreviously glued together side flaps 21 and 22, but the closure ap 7 isleft open.

The ,now nearly completed envelope is guided through a drying zone T fordrying the stripe of adhesive applied vto the openv closure flap 7. Theenvelope while travelling through the drying zone is preferably held bysuitable conventional tools, such as springy grippers.

In the station or position 32, the closure flap 7, the adhesive on whichis now dry, is also folded over and the then finished envelope isstacked in the position or station 33 on the table of the machine.

T he aforedescribed method of the invention has the advantage that forproducing envelopes of different lengths the tools required for carryingout the aforedescribed operations-need not to be changed.

In the event envelopes of different widths are to be produced, it ismerely necessary to set upon the rollers and carries remaining in themachine, tools which have the appropriate width for carrying out theaforedescribed operations in positions 5, 25 and 28. If the dimensionsof the windows are to be changed, a suitably dimensioned tool in thewindow cutting station 18 is, of course, also necessary.

Another advantage of the method of the invention is that the bottom flapand the closure flap 7 are always oriented crosswise of the lengthwiseextending fibers in a paper web. As a result, the bottom flap and theclosure ap tend to curl or wrinkle less when the adhesive is appliedthereto than they would if the flaps extend parallel to the direction ofthe fibers.

Finally, the orientation of the finished envelopes lengthwise of the webpermits the manufacture of lengthwise striped envelopes in an economicalfashion by using a lengthwise striped paper web. Lengthwise stripedopenend envelopes are preferred by postal authorities in many countries.

FIG. 2 shows the application of adhesive to the bottom flap and theclosure flap of so-called self-sealing envelopes and some of thesubsequent operational steps.

In the station or position 28', a stripe 39 of dextrin or other suitablenatural or synthetic gum is applied to the bottom flap 6a and a latexstripe 34 to the closure ap 7a. A corresponding latex stripe 35 isapplied to the main portion of the envelope blank crosswise to thelength thereof.

In the station or position 29', the bottom ap 6a is folded back to beglued to the side flaps which are earlier folded as described. Theenvelope blank is now guided through a dry Zone T to the station orposition 32'. The closure ap is not folded in the position 32', that is,the finished envelopes are delivered to the station or position 33 to bestacked on the table of the machine with the closure flap still open.

FIG. 3 shows a flow diagram for the gumming of the bottom and closureflaps and some of the subsequent operational steps for producingenvelopes to be used for printed matter.

Envelopes for such use require that the bottom or closure flap can beopened and reclosed by the postal authorities for inspection. To permitsuch opening and reclosing, the bottom flap 68 is coated with a specialadhesive which permits a repeated adhesion and reopening in drycondition. Suitable adhesives for the purpose, generally having a latexbase, are well known and generally available in the market and do notconstitute part of the invention.

In the station or position 28", a stripe 51" of dextrin or similarmaterial is applied to the closure ap 7b and simultaneously a stripe 36of the aforementioned special adhesive is applied to the bottom flap 6band a stripe 37 of the same special adhesive is also applied to the midor main portion of the blank.

The now nearly completed envelope is subsequently guided through adrying zone T to a station or position 32 with the bottom flap and theclosure flap left open.

In the position 32, the bottom flap and the closure flap are both foldedback whereby the bottom iiap 6b, which is coated with the specialadhesive, is adhered to the side flaps.

Finally, the finished envelopes are stacked in the position 33 on thetable of the machine.

The concept of the method according to the invention is not limited tothe aforedescribed specific sequence of operational steps for producingenvelopes with gluing of a single side iiap. The sequence of theoperational steps following the separation of the rectangular blanks 3from web 1 may be changed if desirable without departing from the basicconcept of the invention. Furthermore, the concept of the invention alsoincludes the manufacture of differently shaped envelopes, for instance,of envelopes having bOth side flaps glued.

What is claimed is:

1. A method of producing single piece envelopes in continuous operation,said method comprising the steps of feeding a continuous web of uniformwidth along a predetermined path and at a predetermined speed, makinguniformly spaced crosswise cuts through said moving web, each of thecut-off web pieces constituting a preliminary envelope blank,accelerating each of said blanks to a higher predetermined speed causinga lengthwise spacing of said blanks along said path, cutting olfmarginal portions of each moving blank to define side, bottom andclosure flaps, forming preliminary fold lines along the base lines atwhich said iiaps are joined to the main Ibody of the blanks, applyingadhesive at least to one of the side flaps and to the bottom liap on oneside thereof, and folding the side iiaps and the Abottom iiaps upon oneanother along said fold lines.

2. The method according to claim 1 and comprising the step of cutting atleast one window in the main body of successive moving blanks.

3. The method according to claim 2, wherein said Window is cutsubsequent to the forming of the preliminary fold lines in the aps andprior to the folding of the flaps.

4. The method according to claim 1 and comprising the steps of cuttingat least one window in the main body of successive moving blanks, andcovering the window in each blank with a transparent foil.

5. A method of producing single piece envelopes in continuous operation,said method comprising the steps of feeding a continuous web of uniformwidth along a predetermined path and at a predetermined speed, cuttingsaid web crosswise at equal spatial intervals, each cut-off web piececonstituting a generally rectangular envelope blank, accelerating thesuccessively formed blanks to a higher feed speed than the feed speed ofthe continuous web to cause lengthwise spacing of the moving blank-s,cutting off marginal blank portions at the crosswise edges of eachIblank to define side fiaps, a bottom iiap and a closure flap, scoringsaid flaps of each blank at the junction lines thereof with the mainbody thereof to form preliminary fold lines, applying adhesive to atleast one of the side flaps, the bottom and the closure flap on one sidethereof, folding the side aps and bottom aps upon one another along thepreliminary fold lines thereof to adhere said aps to each other, dryingthe adhesive applied to the closure ap, and folding the closure ap alongthe prelllilrninary fold line thereof upon the main body of the bla 6. Amethod of producing single piece envelopes in continuous operation, saidmethod comprising the steps of feeding a continuous web of uniform width.along a predetermined path and at a predetermined speed, cutting saidweb crosswise at equal spatial intervals, each cut-off web piececonstituting a generally rectangular envelope blank, accelerating thesuccessively formed blanks to a CII higher feed speed than the feedspeed of the continuous web to cause lengthwise spacing of the movingblanks, cutting off marginal blank portions at the crosswise edges ofeach blank to define side flaps, a bottom flap and a closure flap,scoring the closure iap and the bottom iiap of successive moving blanksat the junction lines of said iiaps with the main body of the blanks t0form preliminary fold lines, changing the positioning of the blanks inreference to the initial positioning of travel thereof, scoring the sideaps of successive moving blanks at the junction lines of said side apsWith the main body of the Iblanks to form preliminary fold lines,coating at least one side iiap of successive moving blanks withadhesive, folding the side flaps of successive moving blanks upon eachother to adhere the same to each other, coating the bottom and theclosure flaps of successive moving blanks with adhesive, folding thebottom iiap of successive moving blanks upon the folded and Aadheredside flaps, and letting dry the adhesive coating on the closure flap.

7. The method according to claim 6, wherein successive blanks are firstguided along a first substantially rectilinear path of travel and then,without change in axial orientation of the flaps, along a secondsubstantially rectilinear path of travel dening a substantially rightangle with the first path thereby turning each blank through an angle ofin reference to the initial positioning thereof.

8. The method according to claim 6, wherein successive blank-s are eachturned through an angle of substantially 90.

9. The method according to claim 6 and comprising the step of aligningeach blank after changing the position of orientation thereof in apredetermined position in reference to the direction of the path oftravel thereof.

10. The method according to claim 6, wherein at least one flap ofsuccessive moving Iblanks is coated with a self-sealing adhesive topermit reopening of folded-back flaps.

11. The method according to claim 10, wherein the closure ap of eachsuccessive blank is coated with a self-sealing adhesive.

12. The method according to claim 6, wherein at least one of the sideflaps and the bottom flap of each blank are simultaneously coated withadhesive.

13. The method according to claim 6, wherein the flaps of each blank arecoated with different adhesives.

14. The method according to claim 6, wherein one of the side flaps andthe bottom ap are coated with latex and dextrin respectively.

References Cited UNITED STATES PATENTS 2,696,255 12/1954 Heywood.

2,920,539 1/ 1960 Doetsch 93-63 BERNARD STICKNEY, Primary Examiner.

1. A METHOD OF PRODUCING SINGLE PIECE ENVELOPES IN CONTINUOUS OPERATION,SAID METHOD COMPRISING THE STEPS OF FEEDING A CONTINUOU WEB OF UNIFORMWIDTH ALONG A PREDETERMINED PATH AND AT A PREDETERMINED SPEED, MAKINGUNIFORMLY SPACE CROSSWISE CUTS THROUGH SAID MOVING WEB, EACH OF THECUT-OFF WEB PIECES CONSTITUTING A PRELIMNARY ENVELOPE BLANK,ACCELERATING EACH OF SAID BLANKS TO A HIGHER PREDETERMINED SPEED CAUSINGA LENGTHWISE SPACING OF SAID BLANKS ALONG SAID PATH, CUTTING OFFMARGINAL PORTIONS OF EACH OF MOVING BLANK TO DEFINE SIDE, BOTTOM ANDCLOSURE FLAPS, FORMING PRELIMINARY FOLD LINES ALONG THE BASE LINES ATWHICH SAID FLAPS ARE JOINED TO THE MAIN BODY OF THE BLANKS, APPLYINGADHESIVE AT LEAST TO ONE OF THE SIDE FLAPS AND TO THE BOTTOM FLAP ON ONESIDE THEREOF, AND FOLDING THE SIDE FLAPS AND THE BOTTOM FLAPS UPON ONEANOTHER ALONG SAID FOLD LINES.